Electric heating device for heating fluids

Abstract

The invention relates to an electric heating device for heating fluids, comprising at least one heating rod, which has at least one heating element, a housing, which encloses the heating rod and has an inlet opening and an outlet opening, wherein the inlet opening and the outlet opening are interconnected by a winding flow channel. According to the invention, the flow channel forms a helix that has a longitudinal axis, wherein the heating rod is disposed next to the longitudinal axis of the helix and extends through a helically winding wall of the flow channel at a plurality of points.

What is claimed is: 
     
       1. An electric heating device for heating fluids, comprising:
 at least one heating rod, which has at least one heating element; 
 a housing, enclosing the heating rod and having an inlet opening and an outlet opening; 
 a winding flow channel interconnecting the inlet opening and the outlet opening by a winding flow channel, 
 wherein the flow channel forms a helix that has a longitudinal axis, wherein the heating rod is disposed off-center and next to the longitudinal axis of the helix and extends through a helically winding wall of the flow channel at a plurality of off-center points. 
 
     
     
       2. The heating device according to  claim 1 , wherein a plurality of heating rods extends through the helically winding wall of the flow channel. 
     
     
       3. The heating device according to  claim 1 , wherein the heating rod or the heating rods are disposed in parallel to the longitudinal axis of the flow channel. 
     
     
       4. The heating device according to  claim 1 , wherein the flow channel is formed by flow guidance elements that are disposed one on top of the other in the housing and each form a portion of a screw and comprise recesses for the heating rod or the heating rods. 
     
     
       5. The heating device according to  claim 4 , wherein each flow guidance element forms a turn of the screw. 
     
     
       6. The heating device according to  claim 1 , wherein the heating rod comprises a rectangular tube in which at least one heating element is disposed, said heating element being a PTC element. 
     
     
       7. The heating device according to  claim 1 , wherein the heating rod has a cross section having two narrow sides and two broad sides, wherein the broad sides are disposed at a slant with respect to the radial direction of the helix. 
     
     
       8. The heating device according to  claim 1 , wherein the housing is cylindrical. 
     
     
       9. The heating device according to  claim 1 , wherein the heating rod is embedded on at least one end in a casting compound. 
     
     
       10. The heating device according to  claim 1 , wherein a connecting plate protrudes from the heating rod and is inserted into a slot of a circuit support plate. 
     
     
       11. The heating device according to  claim 1 , wherein the flow channel comprises a section that extends in the longitudinal axis of the helix. 
     
     
       12. An electric heating device for heating fluids, comprising:
 at least one heating rod, which has at least one heating element; 
 a housing, enclosing the at least one heating rod and having an inlet opening and an outlet opening; 
 a winding flow channel interconnecting the inlet opening and the outlet opening by a winding flow channel; 
 wherein the flow channel forms a helix that has a longitudinal axis, wherein the heating rod is disposed a distance from the longitudinal axis of the helix and extends through a helically winding wall of the flow channel at a plurality of points; and 
 wherein the flow channel is formed by flow guidance elements that are disposed one on top of the other in the housing and each form a portion of a screw and comprise recesses for the at least one heating rod. 
 
     
     
       13. An electric heating device for heating fluids, comprising:
 at least one heating rod, which has at least one heating element; 
 a housing, enclosing the at least one heating rod and having an inlet opening and an outlet opening; 
 a winding flow channel interconnecting the inlet opening and the outlet opening by a winding flow channel, wherein the winding flow channel forms a helix that has a longitudinal axis, wherein the heating rod is disposed spaced from the longitudinal axis of the helix and extends through a helically winding wall of the flow channel at a plurality of points; and 
 a connecting plate protruding from the at least one heating rod and inserted into a slot of a circuit support plate.